The study analyses new forms of banditry and cattle rustling in north-western Kenya. These phenomena involve both inter and intra-ethnic as well as cross border raids for livestock. The practice is causing great havoc in the area in terms of loss of human lives, destruction of property, stealing of livestock and dislocation of populations. The new forms of violence seem to be the result of multiple cracks in the administrative structures of the state and social norms. The government of Kenya seems to have lost effective control over northwestern Kenya, especially with regard to bandits and cattle rustlers, who have become more militarised and destructive in their operations. The study posits that the roots of these new forms of violence and insecurity can be found in social, cultural, economic, political and historical factors. The study seeks to establish that banditry and cattle rustling are serious threats to internal security, rule of law and democratic governance, which are so vital for political pluralism in Kenya. It is the understanding of these new tendencies and their relative importance, amidst challenges of globalisation, which is central to any research on violence, conflict and conflict resolution in Eastern Africa. Part one of the paper provides a historical background of the pastoral economy and cattle rustling since pre-colonial times. Part two discusses the causal factors of new forms of banditry and cattle rustling. Although most of these factors can be traced to the colonial era, the main focus is on the worsening situation in the last twenty years or so. Part three summarises the socio-economic and political impact of banditry and cattle rustling. In the conclusion, the paper provides a compressed discussion and offers some possible solutions to the banditry and cattle rustling menace.